1. Field of the Invention
The present invention relates to devices for filtering liquids, and more particularly a magnetic filter adapter for removing solid particles from a fluid.
2. Description of the Related Art
Fluid flow systems typically use canister-shaped spin on filters to remove foreign particles from the fluid used to lubricate or cool the moving parts of a mechanical system, such as an engine. Traditional filters typically rely upon a filtration method of removing particles by passing the fluid through a porous material that captures large impurities in the fluid. Many particles, however, are subject to magnetic attraction, such as metal shavings in automobile engine oil from worn engine parts, which are smaller than the openings in the porous material used in a conventional oil filter. Therefore many of the metallic particles in engine oil are not removed by the oil filter and continue to circulate through the engine system causing wear and possible blockages in the system. In addition to unfiltered particles, trapped particles also have a tendency to break loose and travel back into the system causing further damage.
Some current oil filters include an assembly of magnets applied to the outer wall of an oil filter cartridge in order to magnetically capture some of the metal shavings from engine parts. Some of these magnetic assemblies are permanently attached to the filter cartridge, whereas others can be removed upon replacement of the filter. One example of a magnetic assembly for oil filters is disclosed by Cooper in U.S. Pat. No. 5,817,233 entitled “Magnetic Filtering Apparatus.” Cooper's filter apparatus consists of a magnetic member, which surrounds a replaceable oil filter. The magnetic member attracts the metal particles to the sidewall of the filter, thereby removing some of the particles from the main flow direction of the oil through the filter. However, because Cooper's magnetic member is mounted outside of the filter, it does not efficiently remove the metal particles.
Another oil filter with an external magnetic assembly is disclosed by Shoemaker in U.S. Pat. No. 4,613,435 entitled “Magnetic Oil Filter.” Shoemaker's apparatus includes a magnetic plate mounted within the disposable oil filter. Unfortunately, this type of filter is more costly than a conventional oil filter because both the oil filter and magnetic plate need to be replaced once the oil filter has passed its useful lifespan.
It will be appreciated that the use of a removable magnetic filter assembly, auxiliary to a replaceable spin on filter cartridge, would be beneficial in a fluid filtration system. Accordingly, what is needed in the art is an inexpensive and flexible filter system that includes a magnetic filtering capability. The present invention provides such a device.